Laser cooling and trapping of neutral atoms has been employed for the measurement of the total electron impact cross sections of the ground state 62 S 1/2 of 133Cs atoms in the energy range from 80 to 500 eV. The total electron impact cross sections of the cold Cs atoms in the MOT were measured by observing the decay of the MOT after the interaction with the electron beam, and were found to depend only on the electron flux and not on the total number of atoms in the MOT. We confirm and extend the existing data on these measurements.
An atom trapping technique for determining absolute, total ionization cross sections (TICS) out of an excited atom is presented. The unique feature of our method is in utilizing Doppler cooling of neutral atoms to determine ionization cross sections. This fluorescence-monitoring experiment, which is a variant of the ``trap loss'' technique, has enabled us to obtain the experimental electron impact ionization cross sections out of the Cs
62P3∕2 state between
7eV and
400eV. CCC, RMPS, and Born theoretical results are also presented for both the ground and excited states of cesium and rubidium. In the low energy region
(<11eV) where best agreement between these excited state measurements and theory might be expected, a discrepancy of approximately a factor of five is observed. Above this energy there are significant contributions to the TICS from both autoionization and multiple ionization.